A Victorian legal rights group says young people fear they will be unfairly targeted by the state's plan to issue on-the-spot fines to people who swear.

Under the proposed legislation, people could be fined close to $240 for language that is considered indecent or offensive.

But Tiffany Overall from Youthlaw, Victoria's community legal centre for young people, says young people feel they are being targeted.

"The reality is that young people are more commonly using public spaces than other groups in the community," she said.

"What we find with lots of these sorts of on-the-spot-type offences is that young people are feeling targeted by police and so that they will probably be the ones that cop the fine."

Ms Overall says many of the young people she deals with cannot afford to pay the fine.

"What we find is a lot of young people that are fairly financially disadvantaged can't afford to pay it, maybe don't pay it, then there are administrative costs added to it and it just sort of all snowballs," she said.

"It really just compounds the issue rather than resolving the issue."

On the streets of Melbourne this morning, the new law received a mixed reaction.

"In Australian language and our dialect, it's sort of built into our culture and that sort of thing. If you're saying bloody oath and that sort of thing, it's part of our culture," one young person said.

"I suppose it all depends what they say, what words they use. All Australians swear to a certain point. It would depend on the word they were using," a second Melbourne local said.

Another said: "I think there are exceptions. I think the F-bomb or the C-bomb probably shouldn't be heard in public, but I think anything else is fair go."

But Victorian Attorney-General Robert Clark says the laws have been exercised responsibly during a three-year trial due to end in June.

"The police have exercised these powers responsibly over the period of the trial and there's every reason to expect they'll continue to do so in future to make the streets more pleasant places," he said.

Mr Clark admits he has used the odd swear word.

"Occasionally I mutter things under my breath as probably everybody does," he said.

"But this law is not targeted at that; it's targeted at sort of obnoxious, offensive behaviour in public that makes life unpleasant for everybody else."

The reforms are part of the Baillieu Government's broader law and order agenda, which includes minimum jail terms for 16- and 17-year-olds convicted of violent crimes, and protective security officers at suburban police stations.

Mr Clark says the new swear jar should make it easier for police to deal with antisocial behaviour.

"Clearly this sort of loutish, obnoxious behaviour can be very off-putting for many members of the public going about their ordinary business in public places," he said.

"It's contributing to a growing level of antisocial behaviour that Victoria's been experiencing over the last 10 years or so.

"This will give the police the tools they need to be able to act against this sort of obnoxious behaviour on the spot rather than having to drag offenders off to court and take up time and money in proceedings in the court."